Copiers for simplex and duplex copying

Claim 1

In a copier capable of simplex or duplex copying, including a photoreceptor, first and second copy sheet trays, means for feeding copy sheets from said first and second copy sheet trays to said photoreceptor, and a duplex buffer tray, and further including, for said duplex copying, simplexed sheet recirculation means for conveying simplexed copy sheets, which have received an image on only one side at said photoreceptor, to said duplex buffer tray and for refeeding said simplexed copy sheets back from said duplex buffer tray to said photoreceptor to receive a second image on the other sides thereof, the improvement wherein said means for feeding copy sheets comprises a first sheet feeder associated only with said first copy sheet tray and a second sheet feeder commonly associated with both said duplex buffer tray and said second copy sheet tray, and wherein said second copy sheet tray is mounted for movement between a lowered, operative, position in which it is seated within said duplex buffer tray and operatively associated with said second, common, sheet feeder only for simplex copying, and a raised, inoperative, position in which said second copy sheet tray is spaced over said duplex buffer tray and only said duplex buffer tray is operatively associated with said second common, sheet feeder, and wherein said second copy sheet tray is maintained in said raised, inoperative, position during said duplex copying.